Saved Bookmarks
| 1. |
A stone is dropped into a quiet lake and waves move in circles at the speed of 5cm / sec. Atwhen the radius of the circular wave is 8em, how fast is the enclosed area is i |
|
Answer» Step 1:Given :drdt=5cm/s and radius=8cmArea of the circle is πr2Differentiating w.r.t t on both sides we get,dAdt=2πrdrdtStep 2:Substituting for r and drdt we get,dAdt=2×π×8×5=80πcm2/sHence the enclosed area is increasing at the rate of 80πcm2/s |
|